From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srinivas Pandruvada Subject: [PATCH v4 3/3] cpufreq: intel_pstate: Enable PPC enforcement for servers Date: Wed, 27 Apr 2016 15:48:08 -0700 Message-ID: <1461797288-31573-4-git-send-email-srinivas.pandruvada@linux.intel.com> References: <1461797288-31573-1-git-send-email-srinivas.pandruvada@linux.intel.com> Return-path: Received: from mga02.intel.com ([134.134.136.20]:52033 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751019AbcD0WsE (ORCPT ); Wed, 27 Apr 2016 18:48:04 -0400 In-Reply-To: <1461797288-31573-1-git-send-email-srinivas.pandruvada@linux.intel.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: rjw@rjwysocki.net Cc: khlebnikov@yandex-team.ru, linux-pm@vger.kernel.org, Srinivas Pandruvada For platforms which are controlled via remove node manager, enable _PPC by default. These platforms are mostly categorized as enterprise server or performance servers. These platforms needs to go through some certifications tests, which tests control via _PPC. The relative risk of enabling by default is low as this is is less likely that these systems have broken _PSS table. Signed-off-by: Srinivas Pandruvada --- Documentation/kernel-parameters.txt | 5 ++++- drivers/cpufreq/intel_pstate.c | 12 +++++++++++- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4199a1b..52292b2 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1662,7 +1662,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Only load intel_pstate on systems which support hardware P state control (HWP) if available. support_acpi_ppc - Enforce ACPI _PPC performance limits. + Enforce ACPI _PPC performance limits. If the Fixed ACPI + Description Table, specifies preferred power management + profile as "Enterprise Server" or "Performance Server", + then this feature is turned on by default. intremap= [X86-64, Intel-IOMMU] on enable Interrupt Remapping (default) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index c4894ff..7da7672 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -345,6 +345,16 @@ static struct perf_limits *limits = &powersave_limits; #endif #ifdef CONFIG_ACPI + +static bool intel_pstate_get_ppc_enable_status(void) +{ + if (acpi_gbl_FADT.preferred_profile == PM_ENTERPRISE_SERVER || + acpi_gbl_FADT.preferred_profile == PM_PERFORMANCE_SERVER) + return true; + + return acpi_ppc; +} + /* * The max target pstate ratio is a 8 bit value in both PLATFORM_INFO MSR and * in TURBO_RATIO_LIMIT MSR, which pstate driver stores in max_pstate and @@ -368,7 +378,7 @@ static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy) int ret; int i; - if (!acpi_ppc) + if (!intel_pstate_get_ppc_enable_status()) return; cpu = all_cpu_data[policy->cpu]; -- 2.5.5